As someone who also experience pains in their hands after a couple of hours of typing... I started to use the great open source app called ghost-pepper [1] that i found on github and has been my daily driver (its like superwhisrp but oss/free and local) the maintainer is really nice and replies to DMs really quickly too.
As someone that have tried a few of these apps, I really like this one. I dictated this one just now with ghost pepper. Thanks Matt and thanks orliesaurus for sharing it here!
I am big fan of VoiceInk which is also local and open-source. I also maintain this list of all the best open-source ones in this awesome-style GitHub repo. People looking for open-source dictation tools, hope you find something that works for you here: https://github.com/primaprashant/awesome-voice-typing